1. Field of the Invention
The present invention relates to a light source apparatus for an endoscope, which has a programmable memory for storing data used in endoscopic operations.
2. Description of the Prior Art
Various kinds of data may be used on various occasions in a light source apparatus for an endoscope, for example, on setting conditions for effecting automatic exposure photographing, on setting a brightness level of illuminating light during observation, or on setting letters which are to be superimposed on a picture taken through the endoscope. Such data must be input by an operator (e.g., a doctor). It is however, troublesome to input necessary data on each and every particular occasion.
Accordingly, it is conventional practice to store data that has a high probability of frequent use in a random access memory (RAM), which is connected directly to a system bus in a microcomputer.
In such a light source apparatus, however, an ignition noise is generated when a light source, such as a xenon lamp, is turned on, and it is also likely that external noise from an external device may enter the apparatus.
In conventional arrangements having a RAM connected directly to the system bus, such an internal or external noise may destroy, erase or rewrite the data stored in the RAM, resulting in maloperation when the system is controlled afterward on the basis of the affected data.